Within minimally invasive surgery, there is a recognized need for simple devices such as graspers, dissectors, scissors, and other basic surgical instruments. These instruments are necessary in order to perform simple functions during surgical procedures. Specifically, devices such as graspers are necessary in order to properly clear the work site so that the tissue to be worked on may be isolated and surgery may be performed. Scissors may be needed in order to make an appropriate cut in tissue. Dissectors can be necessary to separate one portion of tissue from another. These instruments also enable other, larger instruments, such as staplers and ligating clip appliers, to have sufficient volumetric room to perform effectively during procedures such as appendectomies, cholecystectomies, herniorrhaphies, etc.
Traditionally, minimally invasive surgical instruments such as graspers, dissectors, scissors and the like have been mounted on generally straight shafts. These shafts may or may not have been able to rotate about their longitudinal axes. Nonetheless, there has been perceived a need for the end effector portion of the shaft to be able to angulate with respect to the longitudinal axis of the shaft. This would enable the surgeon to attack tissue to be operated upon from an oblique angle. In fact, it may be desirable to have the shaft angulate up to 90.degree. with respect to the longitudinal axis of the shaft. In many ways, this function can be analogized to the capability of the human hand to rotate around the "axis" of the arm, and also "angulate" about the wrist. Of course, while the hand is able to function with pure rotation, the degrees of freedom given by wrist action are much greater and in many ways enhance the ability of the hand to perform simple daily functions.
Thus, there is perceived a need for a minimally invasive surgical instrument having an end effector portion which is capable of angulating with respect to the longitudinal axis of the instrument. It would additionally be desirable to have an end effector portion which, in addition to being able to angulate with respect to the longitudinal axis of the instrument, includes means for permitting adjustment of the angular position of the end effectors about the central axis of the end effector portion.